If you've also faced the issue of your mobile phone screen freezing suddenly, then have a look at this article. I use a Samsung Galaxy Grand Quattro and to my surprise its screen suddenly stopped responding one day. Only the side buttons were working and the touchscreen did not work at all. I took the mobile to the local repair shops and told them that sometimes the mobile screen works and sometimes does not. Some of them suggested me to change the entire touch screen panel which would've cost me a bomb. After a bit of troubleshooting myself, I finally found the solution to the problem.

Here are some of the steps you should try if you also face a similar issue:

1) Remove the battery and leave phone for 10 minutes, re-insert the battery, restart and check.

3) Check the storage of your mobile (phone memory and memory card both). There should be enough space in the internal as well as external memory card. If not, remove unnecessary apps, media, games etc. Move apps, games in the external memory card if possible to free-up space in phone memory.

4) Try to boot the phone in safe mode. You can enter into safe mode by switching on the phone and wait until the Samsung symbol appears. When Samsung logo appears, press the 'volume down' key continuously till the display comes on with a safe mode message. In safe mode you can call/message and do all the basic things but you cannot use third party apps. Now continue to use the mobile in safe mode for some time. If the touchscreen still hangs and stops responding after doing this step, follow step 5.